The purpose of the study was to evaluate the feasibility of deformable image registration (DIR) in assessing cumulative dose distributions of the combination of external beam radiotherapy (EBRT) and fractionated intracavitary brachytherapy (ICBT) for cervical cancer. Three-dimensional image data sets of five consecutive patients were used. The treatment plan consisted of whole pelvic EBRT (total dose: 45 Gy in 25 fractions) combined with computed tomography (CT)-based high-dose rate ICBT (≥24 Gy in 4 fractions to the high risk clinical target volume (HR-CTV)). Organs at risk and HR-CTV were contoured on each CT images and dose-volume parameters were acquired. Pre-imaging preparations were performed prior to each ICBT to minimize the uncertainty of the organ position. Physical doses of each treatment were converted to biologically equivalent doses in 2 Gy daily fractions by the linear quadratic model. Three-dimensional dose distributions of each treatment were accumulated on CT images of the first ICBT using DIR with commercially available image registration software (MIM Maestro®). To compare with DIR, 3D dose distributions were fused by rigid registration based on bony structure matching. To evaluate the accuracy of DIR, the Dice similarity coefficient (DSC) was measured between deformed contours and initial contours. The cumulative dose distributions were successfully illustrated on the CT images using DIR. Mean DSCs of the HR-CTV, rectum, and bladder were 0.46, 0.62 and 0.69, respectively, with rigid registration; and 0.78, 0.76, and 0.87, respectively, with DIR (p <0.05). The mean DSCs derived from our DIR procedure were comparable to those of previous reports describing the quality of DIR algorithms in the pelvic region. DVH parameters derived from the 2 methods showed no significant difference. Our results suggest that DIR-based dose accumulation may be acceptable for assessing cumulative dose distributions to assess doses to the tumor and organs at risk in combined radiotherapy for cervical cancer under pre-imaging preparations.

Definitive radiotherapy for cervical cancer consists of external-beam radiotherapy (EBRT) and brachytherapy. In EBRT, a central shield (CS) reduces the dose to the rectum and bladder. The combination of whole-pelvic (WP)- and CS-EBRT and brachytherapy is the standard radiotherapy protocol in Japan. Despite clinical studies, including multi-institutional clinical trials, showing that the Japanese treatment protocol yields favorable treatment outcomes with low rates of late radiation toxicities, dose–volume parameters for the Japanese treatment protocol remain to be established. We conducted a retrospective dose–volume analysis of 103 patients with uterine cervical cancer treated with the Japanese protocol using computed tomography–based adaptive brachytherapy. The 2-year overall survival and 2-year local control rates according to FIGO stage were 100% and 100% for Stage I, 92% and 94% for Stage II, and 85% and 87% for Stage III–IV, respectively. Late adverse effects in the rectum and bladder were acceptable. Receiver operating characteristic analysis discriminated recurrence within the high-risk clinical target volume (HR-CTV) (n = 5) from no local recurrence (n = 96), with the optimal response obtained at a dose of 36.0 Gy_EQD2 for HR-CTV D90 and 28.0 Gy_EQD2 for HR-CTV D98. These values were used as cut-offs in Fisher exact tests to show that high HR-CTV D90 and HR-CTV D98 doses for brachytherapy sessions were significantly associated with tumor control within the HR-CTV. These data suggest a contribution of brachytherapy to local tumor control in WP- and CS-EBRT and brachytherapy combination treatment, warranting validation in multi-institutional prospective studies.

To clarify the efficacy of palliative radiotherapy for the relief of symptoms due to skin invasion in patients with breast cancer. We conducted a multi-institutional prospective observational study of patients who received palliative radiotherapy for skin invasion due to a primary lesion or chest wall recurrence. Bleeding/discharge, offensive odor, pain and QOL scores were evaluated before and 1, 3 and 6 months after radiotherapy. Twenty-one patients were assessed. Sixteen patients (76%) received 36 Gy in 12 fractions. The mean (±1 SD) score of bleeding/discharge was 1.90 ± 0.89 before radiotherapy, 1.50 ± 0.74 at 1 month, 0.47 ± 0.58 at 3 months, and 0.82 ± 1.04 at 6 months (P = 0.001). The mean score of offensive odor was 1.21 ± 1.38 before radiotherapy, 0.71 ± 0.92 at 1 month, 0.20 ± 0.41 at 3 months, and 0.27 ± 0.62 at 6 months (P = 0.008). The mean score of pain was 2.90 ± 1.22 before radiotherapy, 3.05 ± 1.36 at 1 month, 3.29 ± 1.10 at 3 months, and 3.31 ± 1.54 at 6 months (P = 0.431). The mean total score of QOL-ACD/QOL-ACD-B was 126.2 ± 24.5 before radiotherapy, 130.3 ± 26.3 at 1 month, 136.2 ± 26.6 at 3 months, and 126.6 ± 32.8 at 6 months (P = 0.178). Palliative radiotherapy for skin invasion in patients with breast cancer might be effective, especially for the relief of bleeding/discharge and offensive odor.

The prognostic value of rectal invasion is still unclear in stage IVA cervical cancer. The objective of this study is to evaluate patient outcome and prognostic factors in stage IVA cervical cancer treated with radiation therapy. A retrospective review of the medical records of patients treated with definitive photon radiation therapy for pathologically proven stage IVA cervical cancer between 1980 and 2010 was performed. Eligible patients for the present study were diagnosed with clinical stage IVA cervical cancer by cystoscopy or/and proctoscopy, and they received definitive radiation therapy consisting of a combination of external beam radiotherapy and high-dose-rate brachytherapy. All patients underwent CT scans of the abdomen and pelvis. Among the 67 stage IVA patients studied, 53 patients were stage IVA on the basis of bladder invasion, 7 according to rectal mucosal invasion, and 7 because of both bladder and rectal mucosal invasion. Median follow-up of all patients and surviving patients was 19 months (range, 2–235 months) and 114 months (range, 14–223 months), respectively. The 5-year local control (LC), disease-free survival (DFS), and overall survival (OS) rate were 55, 17, and 24 %, respectively. Rectal invasion had significant impact on DFS, but bladder invasion had the opposite effect (p = 0.00006 and 0.005, respectively). There were significant differences of LC, DFS and OS rates between patients with and without rectal invasion (p = 0.006, 0.00006 and 0.05, respectively). Patients with stage IVA cervical cancer had poor prognosis, with 5-year survival of only 24 %. Furthermore, in stage IVA, rectal invasion might be a worse prognostic factor than bladder invasion.

A phase I study was performed to determine the recommended dose of carbon ion radiotherapy and 3D image-guided brachytherapy for histologically confirmed stage II (≥4 cm), III, or IVA cervical cancer. Dose-limiting toxicities (treatment-related toxicities occurring within three months from the start of carbon ion radiotherapy) included Grade 3 non-hematological toxicity, Grade 4 hematological toxicity, or interruption of treatment for more than two weeks due to treatment-related toxicities. Carbon ion radiotherapy consisted of whole-pelvic irradiation with 36.0 Gy (relative biological effectiveness) in 12 fractions and local boost with 19.2 Gy in four fractions for the primary site, and for positive lymph nodes. Three sessions of three-dimensional (3D) image-guided brachytherapy were administered after completion of carbon ion radiotherapy. Weekly cisplatin at a dose of 40 mg/m² was given concurrently. At a dose level of one, a total rectosigmoid D2cc dose between 67.2 Gy and 71.3 Gy at a biological equivalent dose of 2 Gy per fraction from carbon ion radiotherapy and 3D image-guided brachytherapy was prescribed. Six patients were enrolled into this dose level. No patients developed the pre-defined dose-limiting toxicities. For late toxicities, however, one patient developed Grade 3 rectal hemorrhage requiring transfusion at 10 months after treatment. The median survival time was 50.0 months for the five surviving patients. No further dose escalation was performed, and we determined the dose of level one as the recommended rectosigmoid dose. Although our results are preliminary, the study regimen encourages further investigation (registration: UMIN000013340).